Power supply tower



FIG. 1 is a perspective view of a power supply tower;

FIG. 2 is a first side view thereof;

FIG. 3 is a second side view thereof;

FIG. 4 is a third side view thereof;

FIG. 5 is a fourth side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines in the drawings are for the purpose of illustrating portions of the power supply tower that form no part of the claimed design. 

CLAIM I claim the ornamental design for a power supply tower, as shown and described. 